0
What else can I help you with?
For a 3 phase alternator why there is an AC voltage generated in the absence DC excitation?
due to residual magnetism
How residual magnetism present inside the self excited generator?
Residual magnetism in a self-excited generator refers to the small amount of magnetism that remains in the magnetic core after the generator has been de-energized. This residual magnetism is crucial for the initial excitation of the generator because it provides the necessary magnetic field to induce voltage when the generator is started. As the rotor turns, the residual magnetism induces a small voltage in the stator windings, which, when connected to the field windings, enhances the magnetic field and leads to self-excitation, allowing the generator to generate power. Without sufficient residual magnetism, the generator may fail to start or produce voltage.
How the doubly fed induction generator build up voltage?
If a self-excited generator lost all its residual magnetism, can it build up an output voltage?
Can you explain why there is an armature voltage even the field current is zero?
An armature voltage can exist even when the field current is zero due to residual magnetism in the rotor of the machine. This residual magnetism allows the machine to produce a small amount of magnetic flux, which can induce a voltage in the armature windings when they rotate. Additionally, if the machine is connected to a load or is being driven by an external source, it may still generate a voltage despite having no field current.
What is meant by flashing a field in excitation?
A generator needs to have residual magnetism in its field coils to start the generation of electricity. A generator that has not been run in a long time will loose this magnetism. Because the field voltage is a DC supply, a battery across the field wiring will energize the coils instantaneously. Doing this several times will cause sparking when the contact to the battery is broken, hence the flash. This intermittent energizing and de-energizing will bring the residual magnetism back into the field coils. When the generator is started, the voltage output should rise to its normal level. If it does the magnetizing of the field coils to bring back the residual magnetism will have worked.
For a 3 phase alternator why there is an AC voltage generated in the absence DC excitation?
due to residual magnetism
How is automotive alternator initially excited?
An automotive alternator is initially excited through a process called residual magnetism. When the engine starts, the alternator's rotor, which contains permanent magnets or is electromagnetically induced, generates a small magnetic field due to residual magnetism. This initial magnetic field induces a small alternating current (AC) in the stator windings. Once the engine runs, the voltage regulator takes over, supplying a larger current to the rotor's field windings to increase output.
How residual magnetism present inside the self excited generator?
Residual magnetism in a self-excited generator refers to the small amount of magnetism that remains in the magnetic core after the generator has been de-energized. This residual magnetism is crucial for the initial excitation of the generator because it provides the necessary magnetic field to induce voltage when the generator is started. As the rotor turns, the residual magnetism induces a small voltage in the stator windings, which, when connected to the field windings, enhances the magnetic field and leads to self-excitation, allowing the generator to generate power. Without sufficient residual magnetism, the generator may fail to start or produce voltage.
If a selfexcited generator has lost all of its residual magnetism can it build up an output voltage?
yes
How the doubly fed induction generator build up voltage?
If a self-excited generator lost all its residual magnetism, can it build up an output voltage?
Can you explain why there is an armature voltage even the field current is zero?
An armature voltage can exist even when the field current is zero due to residual magnetism in the rotor of the machine. This residual magnetism allows the machine to produce a small amount of magnetic flux, which can induce a voltage in the armature windings when they rotate. Additionally, if the machine is connected to a load or is being driven by an external source, it may still generate a voltage despite having no field current.
Why dc shunt generator can not induce any voltage with rated speed?
Two things could have occurred. (1) wrong direction of rotation causing loss of residual magnetism or (2) loss of residual magnetism over long period of no use. can be remedied by "flashing" the shunt field winding howlumf
What is meant by flashing a field in excitation?
A generator needs to have residual magnetism in its field coils to start the generation of electricity. A generator that has not been run in a long time will loose this magnetism. Because the field voltage is a DC supply, a battery across the field wiring will energize the coils instantaneously. Doing this several times will cause sparking when the contact to the battery is broken, hence the flash. This intermittent energizing and de-energizing will bring the residual magnetism back into the field coils. When the generator is started, the voltage output should rise to its normal level. If it does the magnetizing of the field coils to bring back the residual magnetism will have worked.
Why an input voltage exists for the motor started to move?
because of the residual magnetic flux that exists in the motor initially due to the poles
Why an input voltage exists for the motor just started to move?
because of the residual magnetic flux that exists in the motor initially due to the poles
What is meant by residual voltage in a dc generator?
poles are partially magnetized this causes some voltage called residual voltage
Why small voltage is built up immediately in rotating shunt machine even without field excitation?
In a rotating shunt machine, a small voltage can be generated even without field excitation due to residual magnetism in the rotor. This residual magnetism creates a weak magnetic field, which induces a small voltage in the armature windings as the rotor spins. Additionally, the armature reaction can enhance this effect slightly, allowing for voltage to build up immediately upon rotation. The small voltage may not be sufficient for practical use but demonstrates the machine's inherent capacity to generate some electrical output.
